1. Field of the Invention
The present invention generally related to a hand tools, and more specifically to a retractable utility knife with a quick release blade mechanism.
2. Description of the Prior Art
Conventional utility knives have various types of structures including fixed, foldable and retractable. They are generally used to cut paper, fabric, and leather. The Chinese Patent Application No. 93208241.6 (Publication Date: Jun. 22, 1994) disclosed “a retractable rope-cut utility knife”, in which a blade stored in a handle is extended out step by step by moving a slider. However, it is not convenient to replace the blade. The Chinese Patent Application No. 03223149.0 (Publication Date: Dec. 24, 2003) disclosed “a combined utility knife”. It is convenient to replace a blade by arranging the blade in a groove of the handle assembly and using a top cover in connection with a lock member. However, the following problems exist. The structure is complex; when replacing a blade, a user needs to release the lock member first and then rotate the top cover, which is complicated and inconvenient. The Chinese Patent Application No. 20042010202117.2 (Publication Date: Feb. 8, 2006) disclosed “a utility knife” in which a blade is arranged in a mounting groove of a handle assembly and a fixing hole is provided in the handle assembly. A bolt anchored in the fixing hole secures the blade. This utility knife is also disadvantageous because extra tools are used when the blade is replaced.